Answer:
C≈25.13ft
Step-by-step explanation:
C=2πr=2·π·4≈25.13274ft
I hope this helps you
121=11.11
a^2-11^2
(a-11). (a+11)
a.a+11a-11a-11.11
a^2+0-121
a^2-121
11) -x + y = -1 ; 2x - y = 0
y = -1 + x ; 2x - (-1+x) = 0 ⇒ 2x + 1 - x = 0 ⇒x = -1
y = -1 + (-1) ⇒ y = -2
12) -2x + y = -20 ; 2x + y = 48
y = -20 + 2x ; 2x + (-20 + 2x) = 48 ⇒ 2x -20 + 2x = 48 ⇒ 4x = 48 + 20
4x = 68 ⇒ x = 68/4 ⇒ x = 17
y = -20 + 2(17) ⇒ y = -20 + 34 ⇒ y = 14
13) 3x -y = -2 ; -2x + y = 3
y = 3 + 2x ; 3x - (3 + 2x) = -2 ⇒ 3x - 3 - 2x = -2 ⇒ x = -2 + 3 ⇒ x = 1
y = 3 + 2(1) ⇒ y = 3 + 2 ⇒ y = 5
14) x - y = 4 ; x - 2y = 10
x = 4 + y ; (4 + y) - 2y = 10 ⇒ 4 + y - 2y = 10 ⇒ 4 - y = 10
⇒ -y = 10 - 4 ⇒ -y = 6 ⇒ y = -6
x = 4 + (-6) ⇒ x = 4 - 6 ⇒ x = -2
15) x + 2y = 5 ; 3x + 2y = 17
x = 5 - 2y ; 3(5-2y) + 2y = 17 ⇒ 15 - 6y + 2y = 17 ⇒ -4y = 17 - 15
⇒ -4y = 2 ⇒ y = -2/4 ⇒ y = -1/2
x = 5 - 2(-1/2) ⇒ x = 5 + 2/2 ⇒ x = 5 + 1 ⇒ x = 6
Answer:
6 units
Step-by-step explanation:
Remember the formula for the area of a rectangle: A = lw
What we know:
A=48
w = l-2
Substitute A for 48 and w for l-2 into the equation
A = lw
48 = l(l-2) Use the distributive property. Multiply over the brackets.
48 = l² - 2l
Rearrange the equation to standard form (0 = ax² + bx + c) to use quadratic formula.
0 = l² - 2l - 48
a = 1 ; b = -2 ; c = -48 State the variables for the quadratic formula
Substitute a, b and c to find the length:
Simplify
Split the equation at the ± for adding and subtracting. Then decide which answer is correct, or if both of them are possible answers.
This is "inadmissable", or impossible because the length can't be a negative value.
Length of the rectangle
Use the formula for the area of a rectangle
Substitute the length and area, then isolate "w" for the width
A = lw
48 = (8)w
48/8 = w
w = 6
Therefore the length of the rectangle is 6 units.
